80mm f/5.6 El-Nikkor and some other lenses I'm playing with

[PaulFurman]

First off, let me mention I searched for earlier discussion and found one thread that gave some interesting details about different versions. The search function here doesn't work well so I used google to search the domain & found it in a 'test' section... perhaps it's not searching active articles?
I use this in the google search box (without brackets):
[80mm el-nikkor site:photomacrography.net]
or as a link:
http://www.google.com/#q=80mm+el-[url]n ... graphy.net

Anyways, I have the newer version that only stops down to f/32 (vs 45) and it seems to work great at around 1:1. I've got a 105 VR Nikkor but this is a heck of a lot smaller & easier to work with on a bellows. I'm really not that impressed with the 105 anyways. I'm pretty new at going beyond 1:1 & am loving the info on this forum.

A while ago I tested the 80/5.6 reversed & front - it didn't seem to make any difference so I'm using it in the normal position. I've used it with other lenses in front also and it seems a useful thing.

I hear a lot of mention of the 50mm f/2.8 El-Nikkor in here. Is that a much different lens?

I also have a 150mm f/4.5 Spiratone bellows lens, which doesn't seem very good or useful. It came with a bellows from ebay along with a 35mm f/3.5 Spiratone which is very useful but not spectacular. I'm awaiting delivery of a Canon 35mm f/2.8 bellows lens to replace it if anyone wants the Spiratone. BTW, the Spiratone bellows is a very unusual model with tilts & shifts in front & back but essentially worthless because it's not sturdy at all. I've also tinkered with all sorts of Ai Nikkors reversed & whatnot but those don't really seem all that great for macro. I can come up with all kinds of crazy magnifications but the quality doesn't really match up & it seems like it's just wasting pixels.

One other lens to play with is I think from a projector, I forget exactly, it's really dirty & old but can achieve 12:1 on the front of the 150mm lens but as I said, the quality isn't worth serious use. But maybe I'm just not using it right. Here's a pic of that one:


I'm not at all sure I want to get into more than about 5:1 magnification which the Canon should work for, maybe I can use that to experiment though & see if it's worth pursuing. This is all using a PB-4 bellows and an xyz stage I built with pretty tight working room on a D700. I'm just getting into stacking too. Any thoughts or comments appreciated.

[rjlittlefield]

The search function here doesn't work well so I used google to search the domain & found it in a 'test' section... perhaps it's not searching active articles?

Correct. The regular forums are not covered by any of the standard search engines. That was an administrative decision made by prior management in response to several different issues, mostly resource limitations. Many of those limitations have gone away, but somehow we've never taken the remaining step of opening the forums to the search engines. Thanks for the nudge.

In the meantime, the most important thing about the builtin search function is to check the "all terms" button or include lots of AND in your query. The default is "any terms", which almost always gives you way more hits than you wanted, most irrelevant.

A while ago I tested the 80/5.6 reversed & front - it didn't seem to make any difference so I'm using it in the normal position.

At 1:1, reversing doesn't really do much because the conjugate distances don't change. The need for reversing kicks in when you're trying to take a lens designed for very low magnification (say 1:10, typical of a 35mm enlarging lens) and stick it on a lot of extension to get high magnification (say 3:1, photographing a large fly at full frame)

I hear a lot of mention of the 50mm f/2.8 El-Nikkor in here. Is that a much different lens?

It is a similar design (6 elements in 4 groups), but the 50 mm covers a narrower field (46 degrees vs 56 degrees) and is 2 stops wider. I do not recall seeing comparative resolution tests. Based on the shorter focal length, wider aperture, and narrower field, it would be reasonable to expect that the 50 mm would have better resolution at high magnification.

I'm awaiting delivery of a Canon 35mm f/2.8 bellows lens...I'm just getting into stacking too. Any thoughts or comments appreciated.

The Canon 35 mm f/2.8 bellows lens should blow away everything else you've mentioned, for high mag stacking applications. Its best aperture is likely to be wide open or close to it -- be sure to check.

--Rik

[PaulFurman]

Thanks Rik!

If I put on extra extension tubes on the bellows for about 200mm, the 80/5.6 El-Nikkor manages about 2.4:1 but it's quite bouncy. It seems to get a tad more magnification reversed but I'd need to stack a few bellows to get more magnification. So I guess that's where the 50mm comes in handy. I originally got the 80mm for tinkering with infinity bellows tilt shift.

It occurs to me part of the problem is f/5.6 is pretty slow when you add the effective aperture and that I might indeed be wasting pixels and would save time shooting smaller jpegs.

I just tested the funky projector lens on the 80/5.6 and it gets 9:1 magnification but it looks like diffraction is eating up all the potential. So I'm guessing a stacked situation like that needs a very fast relay lens. Perhaps worth trying it on a reversed Ai 50mm f/1.2 or 35mm f/1.4, 85/1.4 but I suspect those won't hold up wide open. A lot of variables here. Is that worth pursuing?

Thanks for the search tips, I found a thread discussing how to mount these odd sized threads: http://www.photomacrography.net/forum/v ... php?t=6973 and another thread with sample shots at 3.7x mag, which must have required a huge extension: http://www.photomacrography.net/forum/v ... php?t=6831

[rjlittlefield]

Paul,

A good rule of thumb is to think about what portion you are using of the field that the lens was designed to handle. According to the EL Nikkor manual (see HERE), the 80mm f/5.6 was designed for a maximum film size of 95 mm diagonal, while the 50 mm f/2.8 was designed for 43 mm diagonal. In order to cover that larger field, the designer of the 80/5.6 made compromises that reduce its central resolution, which is the only part you care about.

I don't recognize the lens in your original post, but since you say it can achieve 12:1 on front of the 150, then I guess it must be around 12-15 mm focal length. That's a promising focal length for high mag work, but you'll need to get it oriented as intended.

If you look through it by eye like a magnifying glass, can you get it to focus either way around, or is one of the focal planes inside the barrel?

If one is inside the barrel, then it must be designed to focus on something slightly in front of the end that says "LENS MADE IN JAPAN". That would suggest it's from a microfilm reader or something similar, and in that case you would want to mount it with that end facing the subject.

If both focal planes are accessible, then it could be used either way around but the image quality will be much better one way than the other.

In any case, using it in conjunction with your 150 or any other lens is adding some unnecessary complication that could be degrading the image quality. See Stopping down a lens combo for some discussion of issues there.

I suggest just mounting the thing on the front of your bellows with no other lenses -- stick it through a hole in a body cap or even a piece of thick cardboard so that you can get it mounted.

--Rik

[PaulFurman]

Wow, OK, I assumed it was projecting too small an image circle. Both ends focus to my eye held at about arm's length. It turns out to work best reversed, with the 'made in Japan' label facing the sensor. I did a fast relay lens test before reading this also.

[edit: I had that backwards, forward is better, details below]

Here it is forward on a reversed 85mm f/1.4:
(interesting :-) and has to touch the subject to focus with not much extension)


Reversed by itself:
(poor results)


Forward by itself:
(best results although flare is awful & I might have had light leaks)

[rjlittlefield]

In the first of these three images, I am very worried by what appear to be long radial streaks in the edges and corners. Unless you zoomed while you were making the exposure, those streaks suggest that this image would never become clear, even though the contrast and colors look good.

In comparison, both of the other images appear to be pretty sharp but badly flared. If the lens did come from a projector, then quite possibly it's not designed to resist light coming in from odd angles. In that case, the images would get a lot better if you added some baffles and/or a lens hood to block stray light. See HERE for an illustration of how much improvement a black paper shade can make.

--Rik

[PaulFurman]

Well, I fixed the mount up, did a stack of 24 frames & it ended up no better than a previous one I'd done with the funky lens on the 80/5.6 at f/11 so I'm going to conclude that it's just a stinky lens & not worth tinkering with. Here's the f/11 shot (before figuring effective aperture to be f/32) which is just one shot, no stacking:

Now, that was shot raw & heavily enhanced, the bare lens shots were done as jpegs with minimum contrast & saturation... you can't tell from this size but believe me the bare lens, in the optimized direction (which I actually stated wrongly above) & stacked is real similar in resolution when you zoom in. This tells me I can stop down a whole heck of a lot before exceeding the lens' resolution ability and I wasn't looking at diffraction but just a poor lens. I don't have a simple means of stopping down the bare lens but if I had an aperture to mount in there, the results could be improved somewhat. Anyways the mystery lens is apparently crap. I learned a lot though.

[PaulFurman]

In the first of these three images, I am very worried by what appear to be long radial streaks in the edges and corners. Unless you zoomed while you were making the exposure, those streaks suggest that this image would never become clear, even though the contrast and colors look good.

Yep, the bokeh is all oblong at the edges in a radial pattern. The 85/1.4 was not designed for this magnification & strange things happen I guess. In fact, I was mistaken about which direction was best, thrown off by harsh donut bokeh in the better forward position. The forward position is two stops faster also, perhaps because the back is recessed to about the depth shown in the lens shot with mm scale above.

In comparison, both of the other images appear to be pretty sharp but badly flared. If the lens did come from a projector, then quite possibly it's not designed to resist light coming in from odd angles. In that case, the images would get a lot better if you added some baffles and/or a lens hood to block stray light. See HERE for an illustration of how much improvement a black paper shade can make.

This lens must be incredibly susceptible to flare. The reversed position has it way deep recessed and the light was just barely squeezing through a mm or so working distance gap. The inside is shiny black though like the outside & maybe the sideways light is extra bad.

[PaulFurman]

Alright, this is interesting. Back on the 80/5.6, un-reversed,

I start with a full (190mm not counting another 10 or so mm connection in front) extension & reduce that

by turns on the top front dial of the bellows, zooming out, and compensate focus by moving the rig

closer on the lower focus rail with the bellows. Then I get to about 110mm extension near the middle & I

have to change directions to adjust the bottom focus rail back away as I continue to shorten the

extension distance and zoom out to a lesser magnification. This also happens reversed.

All I can guess is this has to do with the symmetry of the lens somehow.


These measurements are rough but:

extension = read from front edge of front top mount of PB-4 bellows from numbers engraved on the top

rail
rack = read from front edge of PB-4 bellows bottom rail from numbers engraved on the top rail
FOV = read from mm scale subject on 36mm wide sensor
working distance = from front of lens to subject

Un-Reversed:
extension rack FOV working distance
190mm 180mm 18mm 73mm
160mm 160mm 22mm 108mm
120mm 140mm 30mm 127mm
110mm 135mm 35mm 140mm <-- rack reverses here at 1:1
90mm 140mm 45mm 160mm
70mm 165mm 62mm 190mm
60mm 190mm 82mm 240mm
50mm x

Reversed:
extension rack FOV working distance
190mm 190mm 16mm 100mm
160mm 170mm 19mm 108mm
120mm 148mm 26mm 127mm
110mm 140mm 28mm 127mm
90mm 140mm 35mm 146mm <-- rack reverses here at 1:1
70mm 138mm 46mm 170mm
60mm 148mm 53mm 184mm
50mm 162mm 65mm 210mm

Here are test shots for forward & reversed, full size crops, I guess it's not that great really...

Un-reversed 1:1


Reversed 1:1



Un-reversed 2:1



Reversed 2:1


And for comparison, 1.5:1 on the Spiratone 35mm f/3.5

[Harold Gough]

include lots of AND in your query.

Unfortunately, that does not only return results where the terms are linked but also (mostly) where they both/all occur somewhere in the text.

Rik, It is a great pity that the unique resource in these forums cannot be searched more selectively.

Harold

[rjlittlefield]

Then I get to about 110mm extension near the middle & I have to change directions to adjust the bottom focus rail back away as I continue to shorten the extension distance and zoom out to a lesser magnification. This also happens reversed.

All I can guess is this has to do with the symmetry of the lens somehow.
...
110mm 135mm 35mm 140mm <-- rack reverses here at 1:1

Nope, nothing to do with symmetry of the lens.

Think about the thin lens equation: 1/f = 1/o + 1/i, where f = focal length, o distance to object, and i = distance to image.

The value o+i = distance from camera to object.

If the lens sets a fixed value for f, then i and o depend on each other in simple ways, for example i = (fo)/(o-f).

In this case, if you slog through the math (calculus), it turns out that o+i reaches its minimum value when o = i. This is also the place where you get 1:1 magnification.

So, camera-to-subject distance reaches its minimum at 1:1 whenever the lens focal length is fixed and you're focusing by changing the extension.

--Rik

[PaulFurman]

Results from the new Canon 35mm f/2.9 Macro lens in the mail today...
these are stacked from about 10 frames each at max extension on a PB-4 bellows at about 6:1. This was a 'bargain' grade lens from KEH but it arrived looking pristine. I suspect the bargain rating was not due to scratches but from previous returns due to mediocre imaging and previous returns. They have an EX grade offering for $325 (this one was was $250).

I got a bargain grade lens from them before that was total crap and paid return postage, and will do so again, I guess. I haven't yet tested directly against the $50 Spiratone equivalent but this appears to be optimal at f/8 which is not impressive at all. I guess the spiratone was best at f/11. Pfft!

For the record, I have recieved a couple bargain grade lenses from them that performed excellently but were in bad physical condition.

f/2.8


f/4


f/8


f/11

[rjlittlefield]

How depressing. So much for my comment about what to expect from the Canon!

--Rik

[PaulFurman]

OK, I got a replacement and it does indeed perform much better, I finally have something reasonable for these magnifications!

Here's a first test:
http://www.photomacrography.net/forum/v ... 1578#51578

[PaulFurman]

Here's a comparable penny closeup with the 'new' copy:


Wow, that's a lot better. Maybe not perfect but worlds better even counting the difference in post-processing.